This invention relates to an automatic needle insertion device in conjunction with a hypodermic syringe, in which the device is held against the patient at the location where the injection is to be made and, upon release of a trigger the needle is driven into the underlying tissue to a predetermined depth.
Automatic hypodermic syringes of the class of the present invention are well known in the art (U.S. Pat. Nos. 2,671,448 and 2,856,924). While such automatic syringes are useful for their intended purpose, they are complicated in design and operation, and require a syringe or ampoule of unconventional or specific design, and a needle of specific length.
There is need for a simply constructed and easily operated device, capable of being used with conventional syringes of various sizes and having various needle lengths, which will quickly and painlessly insert the needle into the patient. One of the uses of such a device is in the self-administration of medication by persons such as diabetics, highly allergic individuals who must use injectable drugs, or by military personnel where unskilled first-aid must be administered.
It is important in such a device that the contents of the syringe be viewable and the plunger be unencumbered, so that when the needle has been inserted into the underlying tissue the syringe may be aspirated to observe for blood and consequently determine that the needle has not penetrated a blood vessel. It is also important to maintain the syringe immobile during the injection, thereby reducing pain.
The experience of receiving a hypodermic injection should be a relatively painless one. By accomplishing this children and adults will have less apprehension for future injections. The greater the speed of a hypodermic needle penetration into the skin, the less the pain will be perceived. Further, in order to reduce anxiety and fear, the needle should be hidden. This is especially important when approaching children who are to receive an injection. In the case of self injection, it should not be necessary to plunge the needle manually into the skin.
Accordingly, it is the general object of this invention to provide a hypodermic syringe assembly which is automatic in its insertion of the needle into the underlying tissue.
It is another object of this invention to provide a device which is easily adaptable to various size syringes and needle lengths.
It is a further object of this invention to provide a syringe having a window through which the contents of the syringe may be viewed.
It is a further object of this invention to provide a substantial base which may be placed directly against the skin to hold the syringe immobile throughout the duration of the injection.
It is a further object of this invention to provide a syringe wherein the insertion of the needle into the underlying tissue is substantially instantaneous.
It is a further object of this invention to provide a syringe wherein the needle is not visible prior to use.
It is a further object of this invention to provide a syringe wherein the needle does not have to be manually plunged into the skin.